1. Field of the Invention
The present invention relates to a solvent composition useful for liquid delivery chemical vapor deposition of metal organic precursors including metal (.beta.-diketonate) precursors.
2. Description of the Related Art
In the liquid delivery method of carrying out chemical vapor deposition (CVD) processes, a solid precursor is dissolved in an appropriate solvent medium or a liquid-phase precursor is vaporized and the resulting precursor vapor, typically mixed with a carrier gas (such as argon or nitrogen) is transported to the chemical vapor deposition reactor. In the reactor, the precursor vapor stream is contacted with a heated substrate to effect decomposition and deposition of a desired component or components from the vapor phase on the substrate surface.
In such liquid delivery CVD process, a wide variety of solvents have been employed for dissolution or suspension of precursor species, with the liquid solution or suspension being vaporized by various techniques, including flash vaporization on a heated element onto which the liquid containing the precursor is discharged, to volatilize the solvent and precursor species.
In many instances, where a variety of precursors are employed to form a multi-component deposited film in the CVD process, it is desirable to utilize a single solvent medium for the respective precursor species, for ease of operation and simplicity of the process system, thereby avoiding any deleterious solvent-solvent interactions which may occur if different solvent media are utilized for different precursor species. Further, it is desirable that solvent compositions when used for multiple species not interact with the precursor or metal-containing molecules to form unstable chemical solutions, since such instability renders the overall composition unsuitable for liquid delivery.
It therefore is the object of the present invention to provide a novel solvent composition having broad utility for CVD precursors, such as those comprising metal organic compositions with .beta.-diketonate ligands.
Other objects and advantages of the present invention will be more filly apparent from the ensuing disclosure and appended claims.